Cycle Normal Pass in Camera Space
This can be achieved using the Vector Transform node to transform the Normal from World coordinates into Camera coordinates to match the Blender Internal Normal result.

Use the following material :



The key part is the Vector Transform node - this is set to transform the Normal from from World to Camera space. The remaining nodes perform some necessary conversion since BI appears to map camera space in opposite directions to Cycles - so the X and Y both need to be multiplied by -1 (Z is unaffected).

In order to apply the normals to the whole scene (to create a Normal 'pass') you can use the Render Layer Material Override setting to create a whole layer that renders all materials as this and include that pass in the compositor in place of the Normal.

As a comparison, this produces the following result :

Blender Internal : 

Cycles :